Vane-type camshaft adjuster system

ABSTRACT

The object of the invention is to provide an economical vane-type camshaft adjuster system that meets the various requirements of various motors. For this purpose, according to the invention a modular system is provided for the valves of a vane-type camshaft adjuster system. Two different embodiments of valves are proposed. With one embodiment, a valve with mid-locking and without mid-locking may be constructed using the same bush. With the other embodiment, a valve with and without special utilization of the camshaft alternating torques may be constructed using the same bush.

This application claims the benefit of German patent application no. DE10 2009 022 869.1 filed on May 27, 2009, which is incorporated hereinand made a part hereof by reference for all purposes.

BACKGROUND OF THE INVENTION

The invention relates to a vane-type camshaft adjuster system.

From DE 10 2004 039 800 B4 a vane-type camshaft adjuster system for adrive motor is already known. Such a vane-type camshaft adjustercomprises a rotor having five vanes, which are disposedcircumferentially between radially inwardly directed webs of a stator.The vanes divide in each case one pressure chamber into two hydraulicchambers working in opposite directions. One pressure chamber of thesefive pressure chambers has a spring-loaded locking pin, which is alignedparallel to a central axis. When this locking pin is situated in alocking position, the rotor is then fixed relative to the stator in anintermediate position lying between “early” and “late” end positions.

Locking in such an intermediate position that is neither the “early” endposition nor the “late” end position is generally also referred to asmid-locking even if this mid-locking is not effected exactly mid-waybetween the two end positions.

The two hydraulic chambers of the vane-type camshaft adjuster accordingto DE 10 2004 039 800 B4 are controllable by means of anelectrohydraulic 4/4-way valve having a magnet part as an actuator. Forthis purpose the valve has:

-   -   a first working port A for the first hydraulic chamber,    -   a second working port B for the second hydraulic chamber,    -   a tank port T and    -   a supply port P.

Upon starting of the drive motor, by means of the 4/4-way valve in afirst state through simultaneous interconnection of the two workingports the two hydraulic chambers are relieved to an unpressurized staterelative to the tank port T. In this unpressurized state the locking pinmay move into the locking position. The 4/4-way valve in this case is ofa cartridge style of construction. It comprises a bush, inside which ahollow piston is guided in an axially displaceable manner. For thispurpose the piston has at the one end a cup base, which is supportedunder spring loading against an electromagnetically displaceable tappetof the magnet part. The bush has three recesses disposed axiallyadjacent to one another. The piston on the other hand hascircumferential annular control grooves. By displacing the axialposition of the annular control grooves relative to the three recesses,a hydraulic fluid coming from the supply port P is conveyed towards thetwo working ports A, B and/or towards the tank port T.

DE 103 44 816 B4 relates to a further vane-type camshaft adjuster systemfor a drive motor. This reference discloses a cartridge-style 6/4-wayvalve which likewise comprises a bush and a piston disposed inside thebush. The 6/4-way valve has a separate position for removing hydraulicfluid from the two hydraulic chambers so that two spring-loaded lockingdevices may lock in an intermediate position that is neither the “early”end position nor the “late” end position. These two locking devices areradially aligned and disposed in a web of the stator. One of the threeports of the 6/4-way valve is associated exclusively with the twolocking devices.

From DE 10 2006 012 733 B4 and/or DE 10 2006 012 775 B4 a vane-typecamshaft adjuster system having a 4/3-way valve is known. This valve isof a cartridge style of construction. Inserted into the bush at theinside are non-return valves that take the form of band-shaped rings. Bymeans of these non-return valves, camshaft alternating torques areutilized to allow the camshaft adjuster to be adjusted particularlyquickly and/or with a relatively low oil pressure.

From DE 44 22 742 C2 an electrohydraulic valve is already known, whichcomprises:

-   -   a supply port P,    -   a first working port A,    -   a second working port B and    -   a tank port T.

The valve is of a cartridge style of construction and comprises a bushhaving three recesses. Inside the bush a hollow piston is axiallydisplaceable along a running surface. For this purpose there is providedat one piston end a cup base, which is supported under spring loadingagainst a displaceable tappet of an electromagnetic actuator. The pistonhas a circumferential annular control groove. Provided at the two pistonends are outflow recesses, which are aligned transversely of a centralaxis of the valve and lead to the tank port T. Provided on the piston,adjacent to the magnet-side outflow recess, is a circumferential rib,past which a hydraulic flow may be conveyed from the magnet-side workingport to the outflow recess.

The object of the invention is to provide an economical vane-typecamshaft adjuster system that meets the various requirements of variousmotors.

This and other objects are achieved according to the present invention.

SUMMARY OF THE INVENTION

The present invention provides a modular system for the valves of avane-type camshaft adjuster system. Two different embodiments of valvesare proposed. With one example embodiment, a valve with mid-locking andwithout mid-locking may be constructed using the same bush. With anotherexample embodiment, a valve with and without special utilization of thecamshaft alternating torques may be constructed using the same bush.

According to the present invention, one example embodiment of a valve ofthe vane-type camshaft adjuster system is disclosed, which enablesmid-locking with an economical valve. The valve may have detailsdeveloped in a constructionally identical manner for a vane-typecamshaft adjuster system with utilization of the camshaft alternatingtorques.

According to one advantageous aspect of the invention, it is at thepiston end facing the magnet part (i.e. the magnet-side piston end) thatan outflow recess leading to the tank port T and aligned transverselyrelative to the central axis is provided. On the other hand, the otherend is designed as a piston-terminating control edge for directinghydraulic fluid to the tank port T. This, on the one hand, achieves costbenefits as the piston therefore has to be provided with relatively fewrecesses—in particular transverse bores. The piston may also be of arelatively short design, thereby allowing a saving of material not onlyat the piston but also at the bush. Furthermore, a helical compressionspring for spring-loading the piston towards a tappet of the magnet partmay be of a relatively short design as this helical compression springmay be supported relatively close to the piston end. The short overalllength of the 4/4-way valve also offers advantages in terms ofinstallation space.

In a further advantageous manner the bush and the piston according tothe present invention are designed in such a way that it is possible tocreate a design family of valves for vane-type camshaft adjusters thatenables only slight design variations between the valves. These valvesmay be:

-   -   a 4/4-way valve with a special outflow position for the        mid-locking, but without non-return valves for special        utilization of the camshaft alternating torques;    -   a 4/4-way valve with a special outflow position for the        mid-locking and with non-return valves for special utilization        of the camshaft alternating torques;    -   a 4/3-way valve without a special outflow position for the        mid-locking and with non-return valves for special utilization        of the camshaft alternating torques; and    -   a 4/3-way valve without a special outflow position for the        mid-locking and without non-return valves for special        utilization of the camshaft alternating torques.

In particular the magnet parts of such valves be of an identical design.The pistons of a valve without mid-locking need differ from the pistonswith mid-locking only in that in the more complex variant withmid-locking:

-   -   on the one hand a middle outer web is provided, which divides        the annular groove into two annular grooves, and    -   on the other hand a magnet-side outer web is divided by means of        an annular groove into two outer webs.

For the constructional realization, there is provided on the piston,adjacent to the outflow recess, a circumferential rib, past which ahydraulic flow coming from the magnet-side working port B may beconveyed to the outflow recess. Furthermore, between the magnet part andthe second working port B, a region having an inside diameter that iswidened relative to the running surface is provided, thereby formingbetween this inside diameter and the running surface a run-off edge thatis blockable by the rib. Thus, by virtue of the fact that acircumferential rib always forms the run-off edge relative to the recessof the working port B, the piston need not be installed angularlyoriented relative to the bush. For this reason, it is also possible todispense with an anti-rotation element between the bush and the pistonand hence reduce costs. If, however, the outflow recess were directly toform the run-off edge relative to the recess of the second working portB, an expensive angular orientation would be necessary. The solutionaccording to the invention comprising a circumferential rib forblocking/releasing of the outflow recess to the piston, on the otherhand, makes it possible to allow the piston to run directly along therunning surface that is penetrated by the recess for the working port B.The same applies to the embodiment (as described in the previousparagraph) of the other piston end as a control edge. This spring-sidepiston end may also slide directly along the running surface in theregion of the recess which penetrates this running surface of the firstworking port A, with the result, at this piston end too, that the pistonrequires no angular orientation and/or anti-rotation element. Therunning surface may therefore inexpensively take the form of a borepassing through the entire running region. The internal machining of therunning surface may in this case be carried out by a high-qualitysurface treatment.

In this case, in an advantageous manner the inside diameter of the bushin the axial region between the magnet part and the outer web positionedclosest thereto may be designed with an inside diameter that is widenedrelative to the running surface. For the external machining of the bushit is therefore possible to clamp the bush tightly in a tool, forexample a three-jaw chuck, without the bush being plastically deformedto such an extent that the running surface becomes inoperative.

Further advantages of the invention emerge from the claims, the detaileddescription and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will hereinafter be described in conjunction withthe appended drawing figures, wherein like reference numerals denotelike elements, and:

FIG. 1 shows an example embodiment of a vane-type camshaft adjuster inaccordance with the present invention,

FIG. 2 shows a sectional representation of a 4/4-way valve in a firstexample embodiment of the present invention,

FIG. 3 a sectional representation of the hydraulic part along line II-IIof FIG. 1,

FIG. 4 a hydraulic diagram of the 4/4-way valve of FIG. 2 and FIG. 3,

FIG. 5 shows the hydraulic part of the valve of FIG. 2 in a firstposition,

FIG. 6 shows the hydraulic part according to FIG. 5 in a secondposition,

FIG. 7 shows the hydraulic part in a third position,

FIG. 8 shows the hydraulic part in a fourth position,

FIG. 9 shows the piston of the 4/4-way valve of FIG. 2 to FIG. 8 as asingle part in a perspective view,

FIG. 10 shows another piston for a valve of a vane-type camshaftadjuster system in a second example embodiment of the present invention,

FIG. 11 shows a 4/3-way valve having the piston according to FIG. 10,

FIG. 12 shows a sectional representation of the hydraulic part of the4/3-way valve along line XII-XII of FIG. 11,

FIG. 13 shows a hydraulic diagram of the 4/3-way valve of FIG. 11 andFIG. 12,

FIG. 14 to FIG. 16 show, in views similar to that of FIGS. 2-4, a thirdexample embodiment of a hydraulic part for an electrohydraulic 4/4-wayvalve of a vane-type camshaft adjuster system in accordance with thepresent invention, and

FIG. 17, FIG. 18 and FIG. 19 show, in views similar to that of FIGS.2-4, a fourth example embodiment of a the hydraulic part for anelectrohydraulic 4/3-way valve of a vane-type camshaft adjuster systemin accordance with the present invention.

DETAILED DESCRIPTION

The ensuing detailed description provides exemplary embodiments only,and is not intended to limit the scope, applicability, or configurationof the invention. Rather, the ensuing detailed description of theexemplary embodiments will provide those skilled in the art with anenabling description for implementing an embodiment of the invention. Itshould be understood that various changes may be made in the functionand arrangement of elements without departing from the spirit and scopeof the invention as set forth in the appended claims.

In accordance with an example embodiment of the present invention asshown in FIG. 1, by means of a vane-type camshaft adjuster duringoperation of a combustion-engine drive motor the angular positionbetween a crankshaft, which is not represented in detail, and a camshaft127 is varied. In this case, by rotating the camshaft 127 the openingand closing times of the gas exchange valves are shifted in such a waythat the combustion-engine drive motor produces its optimum outputand/or best possible exhaust gas emissions for the respective rotationalspeed. The vane-type camshaft adjuster in this case enables a steplessadjustment of the camshaft 127 relative to the crankshaft. The vane-typecamshaft adjuster has a cylindrical stator 101, which is connected in arotationally fixed manner to a gearwheel, which is not represented indetail. This gearwheel may be for example a sprocket wheel, over which achain extends. The gearwheel may however alternatively be a toothed-beltwheel, over which a drive belt extends as a drive element. By means ofthis drive element and the gearwheel the stator 101 is in a known mannerdrive-connected to the crankshaft.

The stator 101 comprises a cylindrical stator basic body 103, from theinside of which webs 104 project radially inwards at uniform intervalsover the circumference. Formed between adjacent webs 104 are pressurechambers 105, into which pressure medium is introduced. The introductionof this pressure medium is effected in a controlled and/or regulatedmanner by means of a 4/4-way valve and/or 4/3-way valve in accordancewith the present invention that is described below in connection withthe figures. Protruding between adjacent webs 104 are vanes 106, whichproject radially outwards from a cylindrical rotor basic body 107 of arotor 108. These vanes 106 subdivide the pressure chambers 105 betweenthe webs 104 in each case into two hydraulic chambers 109 and 110.

The webs 104 lie with their end faces sealingly against the outerlateral surface of the rotor basic body 107. The vanes 106 in turn liewith their end faces sealingly against the cylindrical inner wall of thestator basic body 103.

The rotor 108 is connected in a rotationally fixed manner to thecamshaft 127. In order to vary the angular position between the camshaft127 and the crankshaft, the rotor 108 is rotated relative to the stator101. For this purpose, depending on the desired direction of rotationthe pressure medium in the first hydraulic chambers 109 and/or 110 ispressurized, while the second hydraulic chambers 110 and/or 109 arerelieved in the direction of the tank.

The rotor 108 is positively fixable in a rotationally fixed mannerrelative to the stator 101. For this purpose a locking pin 121 isprovided, which is aligned parallel to a central axis 125 of thevane-type camshaft adjuster. This locking pin 121 is preloaded by asmall compression spring and in a locking position of the rotor 108relative to the stator 101 may engage into a location hole 126 of thestator 101. This location hole 126 lies, in terms of the circumference,in an intermediate position between the “early” and “late” endpositions.

FIG. 2 shows a partial section of a proportionally adjustable 4/4-wayvalve 81, which in this embodiment is used for the adjustment of thecamshaft of a combustion-engine drive motor having a vane-type camshaftadjuster.

In this case, the 4/4-way valve 81 takes the form of a cartridge valve.This cartridge valve comprises a hydraulic part 83 and a magnet part 5.The hydraulic part 83 has a piston 13 and a bush 15. The piston 13 runsinside the bush 15 along the running surface 85 thereof. The piston 13is preloaded by means of a helical compression spring 9, which issupported relative to a support ring 11 on the bush 15. The bush 15 isprovided with openings 86, 87, 88, which in the illustrated case arerotationally symmetrical bores. These openings 86, 87, 88 represent thefirst working port A, the second working port B and the supply port P.The arrows indicate the regular oil directions. At the end face of thehydraulic part 83 a central opening 17 is provided for the tank port T.This tank port T lies at right angles to the other three ports A, B andP of the 4/4-way valve 81. The opening 17 for the tank port T liescentrally inside the support ring 11. The helical compression spring 9encircles this opening 17 for the tank port T. The piston 13 is hollow.The piston 13 is provided with outflow recesses 21, which at themagnet-side piston end establish the connection to the hollow space 89of the piston 13. In and around the 4/4-way valve 81 a series of sealsare mounted, which during operation keep the hydraulic fluid away fromthe environment and from the parts not supplied with hydraulic fluid. Inthis case, the seal 25 as a magnet-part seal seals off the magnet part 5from the hydraulic part 83. The tappet 41, which rests against a cupbase 93 of the piston 13, is a tappet 41 that is preloaded withhydraulic fluid and situated in the hydraulic fluid. A pole seal 63 anda non-visible coil seal ensure that the hydraulic fluid situated in themagnet part 5 cannot escape outside, i.e. outside of a housing 27. Thehousing 27 at its side close to the hydraulic part 83 verges into aflange 29 that is provided with fastening openings, i.e. the fasteningbores 31. The pole core 39 succeeding the hydraulic part 83 is connectedby beads 33 to the housing 27. These beads 33 are disposed in the regionof the pole seal 63. Inside the housing 27 a coil, an armature, the polecore 39 and the tappet 41 are disposed. For further details about themagnet part 5 reference is made to DE 10 2004 039 800 B4, which in thisregard is to be regarded as incorporated by reference in thisapplication.

The armature in this case may be moved to and fro between two armaturechambers, which are in fluidic communication with the hydraulic part 83of the 4/4-way valve 81 when the piston 13 is outside of its end stopposition.

On the opposite end of the housing 27 to the opening 17 for the tankport T an electric plug 47 is fastened.

A tappet oil space 77 is connected by the outflow recesses 21 to thecentral opening 17 for the tank port T. This connection of the hydraulicpart 83 to the magnet part 5 of the 4/4-way valve 81 is established bymeans of an edge-formed portion 23. This edge-formed portion 23 isattached laterally to the bush 15.

In the non-energized state of the magnet part 5, the piston 13 blocksoff the rear hydraulic channel (coming from armature chambers) in themagnet part 5 from the tank port T. The helical compression spring 9then experiences no counterforce and is in its outspread, most extendedand relaxed position. All of the hydraulic fluid from the hydraulicchambers 110, 109 of the vane-type camshaft adjuster escapes through theopening for the tank port T. Via:

-   -   corresponding outer webs 50, 51, 52, 53 on the piston 13,    -   corresponding inner edges 54, 55 in the bush 15,    -   the inner circumferential edges 56, 57 of the openings 88, 86 of        the working ports A, B and    -   the outflow recess 21,        the ports A and B are in hydraulic communication with the        opening 17 for the tank port T. Placed in front of the openings        86, 87, 88 of the bush 15 are filters 42, 43, 44, which ensure        that the 4/4-way valve 81 functions also in the event of        contaminated hydraulic fluid.

The inside diameter of the bush 15 in the axial region between themagnet part 5 and a shoulder 34 is designed with an inside diameter thatis widened relative to the running surface 85. This shoulder 34 liesapproximately at the outer web 50 positioned closest to the magnet part5. For the external machining of the bush 15 it is therefore possible toclamp the bush 15 tightly in a three-jaw chuck without the bush 15 beingplastically deformed to such an extent that the running surface 15becomes inoperative.

From FIG. 3 it is evident that for producing the four openings 86 thebush 15 is provided with two bores aligned orthogonally relative to oneanother. The same applies to the openings 87, 88 of the bush 15, whichare not visible in FIG. 3.

FIG. 4 shows the 4/4-way valve 81 in a schematic view. If the coil ofthe magnet part 5 is energized with a first, clearly defined current,the piston 13 moves out of a first position 1 into a second position 2.If the coil is moreover loaded with a stronger current and/or a higherduty factor of the pulse width modulation, the piston 13 moves into thethird position 3. Upon an increase to the strongest defined current, thepiston 13 moves into the fourth position 4. In practice, the positioningof the piston 13 from position 2 via position 3 to position 4 is notstepped. Instead, the volumetric flows rise and/or fall in proportion tothe current strength and/or the duty factor.

FIG. 5 shows, as in FIG. 2 and FIG. 4, the hydraulic part 83 in a firstposition 1, in which upon disconnection, stopping or starting of thedrive motor through simultaneous hydraulic interconnection of the twoworking ports A, B the two hydraulic chambers 110, 109 are relieved toan unpressurized state relative to the tank port T, so that the lockingpin 121 visible in FIG. 1 moves into the locking position and/or intothe location hole 126. The activation of the coil in this case has sucha duty factor that the piston 13 is displaced by a stroke of between 0and 0.2 mm counter to the action of the helical compression spring 9.The supply port P is closed in the direction of the working ports A, Bby the middle outer web 52 and the outer web 53 disposed on thespring-side piston end 90. On the other hand, the hydraulic flow fromthe working port A along the outer web 53 to the tank port T is open. Inthis case, the hydraulic fluid at the spring-side piston end 90 runs viaa circumferential control edge 96 to the tank port T. The hydraulic flowfrom the working port B along an annular groove 91 between the two outerwebs 50, 51, which are positioned close to the magnet part 5, to thetank port T is likewise open.

FIG. 6 shows the hydraulic part 83 in the second position 2. In thiscase, the activation of the coil has such a duty factor that the piston13 is displaced by a stroke of between 0.2 and 0.8 mm counter to theaction of the helical compression spring 9. In this case, the supplyport P, starting from a stroke of 0.2 mm, begins to open for a hydraulicflow to the second working port B. On the other hand, the hydraulic flowfrom this second working port B to the tank port T is closed because thehydraulic pressure is closed by the outer web 50 positioned closest tothe magnet part. The hydraulic flow from the working port A along theouter web 53 to the tank port T is open.

FIG. 7 shows the hydraulic part 83 in the third position 3. In thiscase, the activation of the coil has such a duty factor that the piston13 is displaced counter to the action of the helical compression spring9 into a middle position, which lies at a stroke of 1.8 mm. In thiscase, the supply port P is closed in the direction of the two workingports A, B by the middle outer web 51 and the outer web 53 disposed atthe spring-side piston end 90. Equally, the hydraulic flow from thesecond working port B to the tank port T is closed because the hydraulicpressure is closed by the outer web 50 positioned closest to the magnetpart. The hydraulic flow from and to the first working port A is blockedbecause the outer web 53 at the spring-side piston end 90 is longer inaxial direction than the opening 88 of the first working port A, withthe result that the entire opening 88 is overlapped.

FIG. 8 shows the hydraulic part 83 in the fourth position 4. In thiscase, the activation of the coil has such a duty factor that the piston13 is displaced counter to the action of the helical compression spring9 into a maximum end position, which lies at a stroke of 3 mm. In thiscase, the supply port P is open in the direction of the first workingport A. On the other hand, the hydraulic flow from the second workingport B to the tank port T is open, wherein the hydraulic fluid flowsalong the outer web 50 that is situated at the outermost magnet-sidepiston end 92.

FIG. 9 shows the piston 13 of the 4/4-way valve 83 of FIG. 2 to FIG. 8as a single part in a perspective view.

FIG. 10 shows another piston 213 for a vane-type camshaft adjustersystem in a second example embodiment. This vane-type camshaft adjustersystem however, in contrast to the previous example embodiment vane-typecamshaft adjuster system, has no mid-locking. Nevertheless thedifferences between the two pistons 13, 213 in relation to their overallmanufacturing process are very small. For instance, in contrast to thepiston 13 with mid-locking the piston 213 without mid-locking does nothave an approximately centrally disposed outer web 52. Furthermore,instead of the two magnet-side outer webs 50, 51 only a single outer web151 is provided. This single outer web 151, in terms of the axialdelimitations 98, 99, has the axial delimitations 98, 99 of the piston13 with mid-locking. However, in contrast to the piston 13 withmid-locking, an annular groove 91 is not provided. Otherwise the twopistons 13, 213 are of an identical type of design.

FIG. 11 shows a 4/3-way valve having the piston 213 according to FIG.10. The piston 213 runs inside the bush 15 along the running surface 85thereof. The bush 15 according to this embodiment is in this case of anidentical design to the bush 15 according to the other embodimentaccording to FIG. 2 to FIG. 9.

From the diagram according to FIG. 13 it is however evident that the4/3-way valve of FIG. 11 and FIG. 12 is designed as a 4/3-way valve. Inthis case, the 4/3-way valve has the three positions 2, 3, 4 and isproportionally controllable.

The flow from the supply port P to the first working port A and/or thesecond working port B is accordingly controllable in proportion to thecurrent. In this case, just as in the 4/4-way valve according to FIG. 4,there is a position 3, in which via the run-off edges 200, 201 accordingto FIG. 11 a minimal hydraulic pressure is applied to the two hydraulicchambers 109, 110 working in opposite directions.

The constructionally identical design of the bushes in the case of theuse of different pistons to realize a vane-type camshaft adjuster systemin accordance with the present invention, with and without a specialoutlet position for the mid-locking, may be used also in vane-typecamshaft adjuster systems with special utilization of camshaftalternating torques, such as is described for example in DE 10 2006 012733 B4.

In this regard FIG. 14 to FIG. 16 show in a further example embodimentthe hydraulic part 283 for an electrohydraulic 4/4-way valve of avane-type camshaft adjuster system having a central axis 225. In thisexample embodiment, in contrast to FIG. 2 to FIG. 4, no filters areprovided in front of the openings 286, 288 of the two working ports A,B. In the base of the annular grooves 260, 261 associated with these twoworking ports A, B, however, further openings 262, 263 are provided forutilization of the camshaft alternating torques. In contrast to theopenings 286, 288 that are exclusively blockable from inside by theouter webs 250, 251, 253, the further openings 286, 288 have band-shapednon-return valves 270, 271. In each case a band-shaped non-return valve270 and/or 271 is inserted into an inner annular groove 274 and/or 275radially inside of the further opening 262 and/or 263 of the bush 215.By means of these non-return valves 270, 271 it is possible inaccordance with the method described in DE 10 2006 012 733 B4 for ahydraulic pressure, which in the hydraulic chamber 109 and/or 110 to berelieved rises because of camshaft alternating torques for a short timeabove the level of the hydraulic pressure in the hydraulic chamber 110and/or 109 to be loaded, to be made available in the region of thesupply port P. From this supply port P this hydraulic pressure peakand/or this additional hydraulic fluid flow is then made available,together with the hydraulic pressure applied up by an oil pump 272(visible in FIG. 16) to the supply port P, to the hydraulic chamber 110and/or 109 that is to be loaded.

In this case, a third band-shaped non-return valve 276 is additionallyprovided in an inner annular groove 277. This third non-return valve 276is however a pump protection valve, which is basically of an identicalconstruction to the two non-return valves 270, 271. This pump protectionvalve may however have a different response force.

In an alternative example embodiment of the present invention accordingto FIG. 14, filters are inserted also in the annular grooves 260, 261.

FIG. 17, FIG. 18 and FIG. 19 show in a fourth example embodiment thehydraulic part 383 for an electrohydraulic 4/3-way valve of a vane-typecamshaft adjuster system. This vane-type camshaft adjuster systemhowever, in contrast to the third example embodiment of FIG. 14 to FIG.16, has no mid-locking. In this case, the same bush 215 is used as inthe third example embodiment. The piston 313 however differs from thepiston 213 according to the third example embodiment. Furthermore, theannular groove 291 for the tank port T between the two outer webs 250,251 that is shown in FIG. 14 is not provided. Instead, the single outerweb 351 is not divided into two outer webs 250, 251 but is of anintegral construction. In terms of the axial delimitations 298, 299,this single outer web 351 accordingly has the axial delimitations 298,299 of the piston 13 with mid-locking. A further difference from thethird example embodiment is that an axially approximately middle outerweb 252 is not provided.

The previously described valve design embodiments are not limited toproportional valves but may be used also in on-off valves.

Depending on the operating conditions of the valve, filters may beprovided in front of all of the openings to protect the running surfacesbetween piston and bush.

The hydraulic part of the illustrated valves may also be used in aso-called master valve. In this case, the bush is not connected directlyto the magnet part. Instead, the hydraulic part is disposed centrally inthe rotor of the vane-type camshaft adjuster so that the bush rotatesjointly with the piston. The magnet, on the other hand, is disposed in arotationally fixed manner relative to the cylinder head so that arelative movement occurs between the tappet of the magnet part and thepiston.

The described forms of construction are merely exemplary embodiments. Acombination of the described features for different forms ofconstruction is equally possible. For example, a set of valves may beprovided which includes different embodiments of valves and pistonsdescribed herein. Such a set of valves may have a modular construction.Further, in particular non-described features of the device partsbelonging to the invention are to be gathered from the geometries of thedevice parts that are represented in the drawings.

1. Vane-type camshaft adjuster system for a drive motor, comprising: arotor having at least one vane that divides a pressure chamber formedcircumferentially between two radially inwardly directed webs of astator into two hydraulic chambers working in opposite directions, alocking pin associated with said pressure chamber, which locking pin isaligned parallel to a central axis and which in a locking position fixesthe rotor relative to the stator in an intermediate position lyingbetween “early” and “late” end positions, an electrohydraulic 4/4-wayvalve for controlling the two hydraulic chambers, the 4/4-way valvecomprising: a supply port (P), a first working port (A) for the firsthydraulic chamber, a second working port (B) for the second hydraulicchamber, and a tank port (T), by means of the 4/4-way valve in a firstposition (1) during disconnection, stopping or starting of the drivemotor through simultaneous hydraulic interconnection of the two workingports (A, B), the two hydraulic chambers being relieved to anunpressurized state relative to the tank port (T) so that the lockingpin moves into the locking position, the 4/4-way valve being of acartridge style of construction and comprising a bush, which is providedwith three openings disposed axially adjacent to one another and insidewhich a hollow piston is axially displaceable along a running surface,and a cup base which is provided at the magnet-side piston end, whichcup base is supported under spring loading against a displaceable tappetof a magnet part, the piston comprising: two circumferential annularcontrol grooves, an outflow recess at the magnet-side piston end leadingto the tank port (T) and aligned transversely of the central axis, and acircumferential outer web adjacent to said outflow recess, past which ahydraulic flow may be conveyed from the second working port (B) to theoutflow recess, said circumferential outer web at the spring-side pistonend takes the form of a circumferential control edge for directinghydraulic fluid to the tank port (T).
 2. Vane-type camshaft adjustersystem according to claim 1, wherein an inner running surface of thebush is drilled in one diameter in a region of the openings associatedwith the two working ports (A, B).
 3. Vane-type camshaft adjuster systemaccording to claim 2, wherein an inside diameter of the bush in an axialregion between the magnet part and the outer web positioned closestthereto is designed with an inside diameter that is widened relative tothe running surface.
 4. Vane-type camshaft adjuster system according toclaim 1, wherein the recess associated with the supply port (P) isprovided axially between the openings associated with the working ports(A, B).
 5. Vane-type camshaft adjuster system for a drive motor,comprising: a rotor having at least one vane that divides a pressurechamber formed circumferentially between two radially inwardly directedwebs of a stator into two hydraulic chambers working in oppositedirections, an electrohydraulic 4/4-way valve for controlling the twohydraulic chambers, the 4/4-way valve comprising: a first working port(A) for the first hydraulic chamber, a second working port (B) for thesecond hydraulic chamber, a supply port (P) disposed in relation to acentral axis between said two working ports (A, B), and a tank port (T),the 4/4-way valve being of a cartridge style of construction andcomprising a bush, which is provided with at least four openingsdisposed axially adjacent to one another, of which a first and a secondopening are associated with the one of the two working ports (B and/orA), of which the first opening positioned closer to the supply port (P)is provided with a non-return valve, by means of which hydraulic fluidis directed from the first hydraulic chamber associated with said oneworking port (B and/or A) through the other working port (A and/or B) tothe second hydraulic chamber associated with said other working port (Aand/or B) when: the second opening is closed by a hollow piston, andcamshaft alternating torques raise the hydraulic pressure in the firsthydraulic chamber above the hydraulic pressure inside the bush, insidesaid bush the piston being axially displaceable along a running surfaceand at the magnet-side piston end a cup base is provided, which issupported under spring loading against a displaceable tappet of a magnetpart, wherein the piston comprises: at least one circumferential annularcontrol groove, an outflow recess at the magnet-side piston end leadingto the tank port (T) and aligned transversely of the central axis, and acircumferential outer web adjacent to said outflow recess, past which ahydraulic flow may be conveyed from the spring-side working port (B) tothe outflow recess, said circumferential outer web at the spring-sidepiston end takes the form of a circumferential control edge fordirecting hydraulic fluid to the tank port (T).
 6. Vane-type camshaftadjuster system according to claim 5, wherein an inner running surfaceof the bush is drilled in one diameter in a region of the openingsassociated with the two working ports (A, B).
 7. Vane-type camshaftadjuster system according to claim 6, wherein an inside diameter of thebush in an axial region between the magnet part and the outer webpositioned closest thereto is designed with an inside diameter that iswidened relative to the running surface.
 8. Vane-type camshaft adjustersystem according to claim 5, wherein the recess associated with thesupply port (P) is provided axially between the openings associated withthe working ports (A, B).
 9. Set of valves for a vane-type camshaftadjuster system for a drive motor, comprising: at least two types ofvalves, each valve comprising: a first working port (A) for a firsthydraulic chamber, a second working port (B) for a second hydraulicchamber, a supply port (P), and a tank port (T), an identical magnetpart, an identical bush, and one of a piston with mid-locking and apiston without mid-locking, wherein: the piston with mid-lockingcomprises: two circumferential annular control grooves, an outflowrecess at a magnet-side piston end leading to the tank port (T) andaligned transversely of a central axis, and a circumferential outer webadjacent to said outflow recess, past which a hydraulic flow may beconveyed from the second working port (B) to the outflow recess, saidcircumferential outer web at a spring-side piston end takes the form ofa circumferential control edge for directing hydraulic fluid to the tankport (T); and the piston without mid-locking comprises: at least onecircumferential annular control groove, an outflow recess at amagnet-side piston end leading to the tank port (T) and alignedtransversely of the central axis, and a circumferential outer webadjacent to said outflow recess, past which a hydraulic flow may beconveyed from a spring-side working port (B) to the outflow recess, saidcircumferential outer web at the spring-side piston end takes the formof a circumferential control edge for directing hydraulic fluid to thetank port (T).
 10. A set of valves according to claim 9, furthercomprising: at least one rotor having at least one vane that divides apressure chamber formed circumferentially between two radially inwardlydirected webs of a stator into the two hydraulic chambers working inopposite directions.
 11. A set of valves according to claim 9, whereinthe valve with the mid-locking piston further comprises: a locking pinassociated with said pressure chamber, which locking pin is alignedparallel to a central axis and which in a locking position fixes therotor relative to the stator in an intermediate position lying between“early” and “late” end positions; and wherein by means of the valve in afirst position (1) during disconnection, stopping or starting of thedrive motor through simultaneous hydraulic interconnection of the twoworking ports (A, B), the two hydraulic chambers being relieved to anunpressurized state relative to the tank port (T) so that the lockingpin moves into the locking position.
 12. A set of valves according toclaim 9, wherein: each bush is provided with at least three openingsdisposed axially adjacent to one another and inside which the piston isaxially displaceable along a running surface, and a cup base is providedat the magnet-side piston end, which cup base is supported under springloading.
 13. A set of valves according to claim 12, wherein, in thevalve with the piston without mid-locking, camshaft alternating torquesraise the hydraulic pressure in the first hydraulic chamber above thehydraulic pressure inside the bush.